Elevator door device



June 12, 1934. H, v. MCCORMICK 1,962,319

ELEVATOR DOOR DEVICE Filed June 9. 1932 f7; 2. Eye.

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6/ AT EY V UNITED STATES PATENT OFFICE ELEVATOR noon DEvIoE Harold VQMcCormick, Winnetka, 111., assignor to Westinghouse Electric Elevator Company, Chicago, 111., a corporation of Illinois Application June 9, 1932, Serial No. 616,224

8 Claims.

My invention relates to dash-pots and more particularly to fluid-filled dash-pots such as are employed in connection with the operating mechanisms of elevator doors for checking or slowing the final closing movementof such doors.

One object of my invention is 'to provide a dash-pot construction for door operating devices that may be easily and economically manufa'ctured, installed and maintained in: operation.

Another object is to providefa dash-pot construction that may be easily quickly adjusted to suit any desired operation of the door in connection with which it is employed.

It is also an objectof my invention to provide an adjustable dash-pot construction which shall have a relatively small number of parts.

For a better understanding of my invention, reference may be had to the accompanying drawing, in which Figure 1 is a view in front elevation of an elevator door (only a portion of which is shown) and an operating mechanism therefor comprising a plurality of toggle levers and a spring engine or operator embodying a dash-pot constructed in accordance with my invention;

Fig. 2 is an enlarged view, in section, of the spring engine or operator shown in Fig. 1; and

Fig. 3 is an enlarged view in side. elevation of the piston shown in section in Fig. 2.

Referring more particularly to the drawing, I have illustrated an elevator door 1 as comprising a pair of panels 2 and 3 that are disposed to slide to the left side when the door is opened. To save space, only small portions of the panels are shown.

I have provided a means for opening and closing the door comprising a plurality of toggle levers 4, 5 and 6. The left-hand end of the lever 4 is pivotally mounted by a bolt '7 in a bracket 8 secured to the door frame in which the door is mounted. The other end of the lever 4 is pivotally connected by a bolt 9 to one end of the lever 5, the other end Olf which is pivotally connected by a bolt 10 to one end of the lever 6. The lever 5 is pivotally mounted by a bolt 11 on a fulcrum bracket 12 secured to the inner edge of the panel 2 and the outer end of the lever 6 is pivotally, connected by a bolt 13 to the outer panel '3 so that movement of the levers out of their straight line position will open the door and movement to a straight line position will close the door.

A pin 14 is inserted in the lever 5 in position to be engaged by the slotted portion of the lever 4 for limiting the movement of the toggle levers beyond their straight line position upon closing the door.

As shown, a handle 15 is attached to the lever 5 to provide a means for manually breaking the straight line position of the toggle levers when it is desired to open the door.

A spring engine or operating device 1'7 is provided for actuating the toggle levers to close the door with a gradually decelerating movement after it has been opened.

The operating device 17 comprises a casing 18, adash-pot cylinder 19 secured to the lower end of the casing by a welded joint 20, a piston 21, a piston rod 22 connected to the piston and extending upwardly through a cap 23 on the upper end of the casing, a spring washer 24 mounted on the piston rod in position to rest upon the piston, and a compression spring '25 coiled around the piston rod and placed under compression between the Washer 24 and the cap 23.

The lower end of the dash-pot cylinder or fluidcontaining chamber 19 is pivotally connected by a bolt 27 to a bracket 28 secured to the side wall of the door frame. The upper end of the piston. rod is connected by a clevis 29 and a pin 30 to a projection 31 on the toggle lever 4 so that the broken-line movement of the toggle levers, when the door is opened, will pull the piston rod upwardly and compress the spring 25 to such an extent that it will expand and cause the door to close when the handle 15 is released.

A second compression spring 32, smaller than the spring 25, is coiled around the piston rod 22 in position to be compressed between the spring washer 24 and the cap 23 as the door reaches its full open position, for the purpose of providing additional stored power to start the door from its full open position toward its closed position.

In order that the door operator 17 may also act as a bulier or dash-pot to check the closing movement of the door and let it close softly, the piston 21 is fitted neatly into the dash-pot cylinder 19 which may be filled by removing a filling plug 34 from the cap 23 and pouring a suitable fluid, such as oil, into the dash-pot cylinder to increase the 100 dash-pot action of the piston. The spring washer 24 is provided with a plurality of port holes 35 to permit it to move freely with the piston rod through any fluid that may be disposed in the casing and the dash-pot chamber.

One or more exhaust ports or channels 36 are provided in the piston 21 to permit it to move freely upwardly through the liquid when the door is being opened. The port 36 is provided with a ball check valve 37 that closes when the piston 110 starts on its down movement and thereby main tains the dash-pot action of the piston in the fluid as the door is being closed. A pin 37a retains the ball 37 in the port.

The piston 21 should be firmly fixed to the piston red as by knurling the lower end of the rod and die-casting the piston thereon so that the two will act as one piece. A hole 38 is disposed in the upper portion of the piston rod so that a rod' may be inserted therein to turn the piston rod and piston to any position desired. A look nut 39 is disposed on the screw thread portion of the upper end of the rod to lock the rod in any position to which it may be turned.

In order that the dash-pot action of the piston may be controlled to produce such a retarding effect upon the door as may be desirable, I provide a path for permitting the fluid below the piston to escape at a predetermined rate of flow to the space above the piston, as the piston moves downwardly in the dash-pot cylinder when the door is nearing its closed position.

In accordance with my invention, the path for the escape of the luid comprises a longitudinal channel 40, a transverse channel 41, and an annular channel 42 in the piston in conjunction with a longitudinal groove or channel 43 in the upper portion of the inner side wall of the dashpot cylinder. The channel 40 extends upwardly from the bottom of the piston to a point where it connects with the transverse channel 41, which channel extends outwardly from the channel 40 and opens into the annular channel 42. As shown, the annular channel 42 is cut into the outer periphery of the piston and extends nearly, but not quite, around the piston, a portion 45 of the piston being left intact so that only one channel connects the channel 41 with the groove 43.

The rate of flow of the fluid through the channels is controlled by varying the eifective length of the annular channel 42 which is more restricted in cross sectional area than the connected channels 40 and 41 and the groove 43. If the piston is rotated in a clockwise direction, as in a top plan view, the length of the annular channel 42 between the outer end of the channel 41 and the groove 43 will be decreased. Consequently, the length of the path of the fluid will be decreased and thereby permit the liquid to flow more rapidly. If the piston is rotated in the opposite direction, the length of the channel 42 connecting the groove 43 with the channel 41 will be increased and thereby decrease the rate of flow of the dash-pot liquid.

The operation of the invention is as follows: Assuming that the door panels 2 and 3 are in their closed positions and that the door handle 15 is moved downwardly then the toggle levers 4, 5 and 6 will be broken from their straight line position, thereby causing the door panels 2 and 3 to slide to the left to their open positions. As the door opens, the lever 4 moves to its vertical position and thereby exerts an upward pull upon the piston rod 22 which causes the compression springs 25 and 32 to be compressed between the cap 23 and washer 24. Inasmuch as the piston 21 is firmly fixed to the piston red, the piston also moves upwardly and the oil above it passes through'the port holes 36 thereby permitting the piston to move freely until it reaches its uppermost position.

Assuming now that the handle 15 is released, then the force stored in the compressed springs 25 and 32 causes the piston to move downwardly and thereby actuate the piston rod and the toggle levers 4, 5 and 6 to move the door panels 2 and 3 to their closed positions.

As the doors approach their closed positions, the piston moves downwardly and displaces the fluid in the lower part of the dash-pot cylinder, thereby checking the final closing movement .of the door 1 and causing it to come easily and gently to a stop. The oil displaced from beneath the piston flows upwardly through the channel 40 into the transverse channel 41 through the annular channel 42 to where it reaches and goes out through the vertical groove 43, the rate of flow being controlled by the active length of the channel 42. Hence, the rotative position of the piston with reference to the groove 43 determines the dash-pot effect of the piston.

Assuming that it is desired to still further retard the downward movement of the piston for the purpose of making the final closing movement of the door still slower, then the lock nut 39 on the piston rod is loosened, a rod is inserted in the hole 38 and the piston rod rotated thereby, as desired, in a counter clockwise direction, considered from a top plan view. The rotation of the piston rod rotates the piston to move the opening of the transverse channel 41 away from the groove 13, thereby increasing the length of the channel 42 through which the escaping liquid must flow. After the piston rod is rotated to a point to effect the desired retardation, the lock nut is screwed upwardly to lock the piston rod in the position to which it has been adjusted.

After this adjustment, if the door is opened and closed, as previously described, the retardation will be greater as the door nears its closed position, because the length of the channel 42 through which the escaping liquid must flow will be greater and, therefore, increase the dash-pot action of the piston accordingly.

Therefore, it is seen that I have provided a door operator in which the dash-pot action may be easily and quickly adjusted from a point outside the operator chamber and that the number of parts embodied in the apparatus has been re- 1 duced to a marked degree.

Although I have illustrated and described only one specific embodiment of my invention, I real ize that it is susceptible of wide application and I do not desire to be limited to the precise construction illustrated and described.

I claim as my invention:

1. A dash pot comprising a fluid-containing chamber, a piston for said chamber, said piston having a channel through which the fluid may flow during relative movement of the piston and the chamber, adjustable means for varying the effective length of the channel to vary the retarding effect of the dash pot, and means for locking said adjustable means in the position to which it is adjusted.

2. A dash pot comprising a fluid-containing chamber, a piston for said chamber, said piston being provided with a channel having a restricted portion through which the fluid may flow during relative movement of the piston and the chamber, and means for varying the length of the restricted portion of the channel through which the fluid flows to vary the retarding effect of the dash pot.

3. A dash pot comprising a fluid-containing chamber having a channel opening in its inner wall, a piston for said chamber, said piston having a channel through which the fluid may flow to the channel opening in the chamber during relative movement of the piston and the chamber,

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and means forvarying the length of the channel in the piston through which the fluid flows to they channel opening in the chamber to vary the retarding eil'ect of the dash pot.

4. A dash pot comprising a fluid-containing chamber, a piston for said chamber, said chamber having a groove in its inner wall leading from a point above the bottom of the piston when the piston is in its lowermost position in the chamber to a space above the chamber, and said piston having a channel through which the fluid may flow to the groove during relative movement of the piston and the chamber, and means for varying the length of the channel through which the liquid flows to vary the retarding effect of the dash pot.

5. A dash pot comprising a fluid-containing chamber, said chamber being provided with a channel in the upper portion of its inner wall, a piston for the chamber, said piston having a channel through which the fluid may flow to the first named channel, and means for limiting relative rotation of the, piston and the channel to prevent change in the effective length of the second named channel.

6. A dash pot comprising a fluid-containing chamber having a channel in the upper portion of its inner wall, a piston for said chamber, said piston being provided with a channel through which the fluid may flow to the channel in the chamber, means for adjustably rotating said piston to control the eflective length of the channel therein connecting withthe channel in the chamber, and means for locking the piston in the rotative position to which it has been adjusted.

7. A dash pot comprising a'fluid-containing chamber having a channel opening into the top portion of its inner wall, a piston for the chamber, said piston having an annular channel and a longitudinal channel through which the fluid below the piston may escapeto the channel in the chamber, and means for adjustably effecting relative rotation between the piston and the chamber whereby the length of the annular channel through which the liquid escapes may be controlled to secure any desired rate of retardation, and means for maintaining the relative rotative position to which the piston chamber have been adjusted.

8. A dash pot comprising a fluid-containing chamber having a channel opening into the top portion of its inner wall, a piston for the chamber, said piston having a longitudinal channel, a transverse channel and an annular channel connected to provide a path for the escape of the fluid from below the piston to the channel in the chamber, means for adjustably rotating the piston to control the length of the annular channel through which the fluid flows to the channel in the chamber whereby the rate of retardation of the dash pot may be adjusted as deand the III 

